comparison of two contouring methods of bone marrow on ct & correlation with hematological...

Comparison Of Two Contouring Methods Of Bone Marrow On CT & Correlation With Hematological Toxicities (HT) In Non Bone Marrow Sparing Pelvic IMRT (NBM-IMRT) With Concurrent Cisplatin For

Cervical Cancer

Comparison Of Two Contouring Methods Of Bone Marrow On CT & Correlation With Hematological Toxicities (HT) In Non Bone Marrow Sparing Pelvic IMRT (NBM-IMRT) With Concurrent Cisplatin For

Cervical Cancer

R. Krishnatry*, U. M. Mahantshetty, S. Chaudhri, A. Kanujia, R. Engineer, S. Chopra, S. K. Shrivastava, Tata Memoiral Hosptial, Mumbai, India

Two setsVs.

In cervical cancer patients treated with Non Bone Marrow sparing IMRT (NBM-IMRT) & concurrent cisplatin.

• Compare the volumes & Dose volume parameters (DVH) for contours of bone marrow using two methods of contouring on CT scan

• Correlation of DVH parameters with > grade 2 (RTOG) Hematological Toxicity (HT).

• 47 patients prospectively enrolled & treated in pelvic IMRT (NBM-IMRT) and concurrent

cisplatinum in Phase II trial (NCT00193804).

• The planning CT scans contoured for pelvic bone marrow in two sets: (Fig 1)

- Whole bone using auto-segmentation (WB)

- Free hand (FH) inner cavity of bone

• Various sub-volumes were made in each set as sacrum; ilium; ischium; Lower Pelvis (pubes,

ischia, acetabula, & proximal femora); lumbosacral spine; sacrum & whole pelvis (all sub-

volumes as one)

• Volume & DVH parameters compared for two sets using paired t test

Purpose / Objectives

Conclusion

Materials / Methods

Results

• Free Hand bone marrow cavity volume is a better surrogate of active bone marrow on CT images both in terms of volumes and

DVH parameters.• Only Free hand Whole Pelvis V40 >40% correlated with higher than grade 2 HT • It may be an important marker of high toxicity especially when V10 <90%.

Figure 1. Bone Marrow Contouring using Whole Bone & Free Hand Technique And various sub-volumes in each.

Number of Patients 47

Age (years) - Mean (Range) 49.2 (33-65)

Stage IIB

IMRT dose 50Gy/25#/5Weeks

Brachy Dose 7Gy x 5 #

Transfusion - n(%) Pre-treatment [whole blood only]

On treatment Whole blood

G-CCFPlatelet

 5(11%)

 11 (24.7%)5 (10.6%)2(4.7%)

Chemotherapy (number)Chemotherapy agent / Dose

Mean no of cycles

47/47Cisplatin / 40 mg/m2

4.6

Mean PTV volume (range) cc 1440.37 (974-2352) cc

Table 1: General Characteristics

Comparison of volume

Whole bone (W)

Mean (Range) cc

Bone cavity free hand (F)

Mean (Range) ccF/Wx100 (%)

Sacrum

Ilium

Ischium

Lower Pelvis

LS Spine

Whole Pelvis

147 (105-218)

265 (200-377)

220 (139-369)

417 (295-557)

230 (150-322)

925 (690-1268)

31.4 (18-50)

82.65 (53-139)

49.4 (27-81)

105.9 (70-164)

47.3 (26-77)

240 (170-372)

21.08%

30.94%

22.27%

25.18%

20.43%

25.95%

Table 2: Comparison of Volumes

  SPECT

IMRT [1]

Mean

Anal Ca,

Mell [2]

Mean (SD)

Cervix,

Mell [3]

Mean (SD)

Current,

Whole bone

Mean (SD)

Current, Free

hand

Mean (SD)

Whole pelvis

V10

V20

V30

V40

100

88

66

23

85(15)

75(17)

56(19)

32(17)

91(3.6)

74(6.1)

53(7.5)

28(10.3)

88(5.18)

79.6(5.2)

62.9(6.5)

40(0.45)

86.5 (6.8)

77.5 (6.2)

62.5 (6.5)

40.5 (8.4)

Table 3: Comparison of whole pelvis doses in various studies.

Figure 2: DVH of a Patient Developing Grade 3 Neutropenia

• Significant difference between DVH parameters of two sets (p<0.05) for all sub-volumes.

• Leucopenia, neutropenia, anemia, and thrombocytopenia > grade 2 was seen in 53%, 29.8%, 65.9%, and 10.6%, respectively.

• On both univariate and multivariate analysis only FH whole pelvis V40 ≥40% correlated with >grade 2 leucopenia (Whitney U,

p=0.026) and neutropenia (p=0.05) with OR 4 (CI, 1 .166 Y 13.728 ;P =0.028).

References

1. Roeske et al. Incorp of SPECT bone marrow . Radiother Oncol 2005;77:11-72. Mell et al Association between….IJOBP 2008;70:1431-7. 3. Mell et al Dosimetric predic…. IJROBP 2006; 66 (5):1356–1365.

• Hematological parameters during treatment analyzed for > grade 2 (RTOG) HT as significant toxicity & correlated with DVH parameters using log regression analysis

Article in press in IJGC. Contact : krishnatry@gmail.com

drumeshm@gmail.com

Poster number 2554; E-01